The Hawaiian green sea turtles are amazing and in particular, when SCUBA diving right alongside them underwater. Offering daily scuba diving charters at 9:30 am and 1:30 pm, Rainbow Scuba Hawaii has many options available. The first time divers are truly amazed at the size and grace of these sea turtles swimming under the sea. The fully grown Hawaii green sea turtles weigh on average 300 lbs and are 3 feet long in length. The average life span of sea turtles is around 80 years old.